A conventional method for making blades of a plug is shown in FIG. 15 in which a copper sheet M is punched to form a plurality of blades B juxtaposionally secured on the base sheet, which however may have the following drawbacks:
1. The scraps S as remained on the metal sheet S may waste the raw material of brass about 35-45%.
2. The rear portion B1 of each blade B should be further milled for reducing its thickness available for crimping a wire lead to a power source.
3. If the rear portion B1 of the blade B is not milled to be thinner, a complex welding or soldering process should be further provided for connecting an electric wire.
4. The production cost, such as labor cost, mold making and repair fees or wasting material of scraps, will be increased. Furthermore, the control of product dimensions and the surface finishing of the product is very difficult.
The present inventor has found such drawbacks of a conventional process for making plug blades and invented the present process for making blades with cost-saving methods, but wih good quality.